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Primary funding is provided by The SPE Foundation through member donations

Primary funding is provided by The SPE Foundation through member donations and a contribution from Offshore Europe The Society is grateful to those companies that allow their professionals to serve as lecturers Additional support provided by AIME.

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Primary funding is provided by The SPE Foundation through member donations

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  1. Primary funding is provided by The SPE Foundation through member donations and a contribution from Offshore Europe The Society is grateful to those companies that allow their professionals to serve as lecturers Additional support provided by AIME Society of Petroleum Engineers Distinguished Lecturer Program www.spe.org/dl

  2. The Fracts of Life Martin Rylance Society of Petroleum Engineers Distinguished Lecturer Program www.spe.org/dl

  3. THE “FRACTS” OF LIFE Key Aspects GEOMECHANICS FORMATION PERMEABILITY FRACTURING QA/QC VERTICALS TO HORIZONTALS 3

  4. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” • Non-Operated JV in South-East Asia • Multi-layered sands (1,000 – 14,000 ft). • Produced 13.1 Tcf and 0.4 Bbls liquids. • Deep tight-sand opportunity 0.75 Tcf. • Application of hydraulic Frac technique. • Some 30 years of attempted fracturing. • Spectacularly unsuccessful campaign. 7 Successes 28 Failures where Post Frac production <= Pre-Frac Production 4

  5. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” Multiple Fracturing Service Providers, Expert Fracturing Consultancies … etc reviewed and provided their expert opinion on the causes/solutions. It’s definitely the proppant, no hang on it’s the frac fluid, yes it’s definitely the fluid, oh that didn’t work, then it must be the well integrity then. 5

  6. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” • Independent Frac Reviews Indicated: • Poor fracturing fluid QA/QC (55 lb/Tg). • Poor proppant quality/excessive crush. • Poor well design and casing integrity. • However, each subsequent Campaign would deliver an equivalent cycle of Review, Absolute Certainty of Root-Cause, Execution, Failure, Pause and “rinse and repeat”. 6

  7. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” • Poor fracturing fluid QA/QC (55 lb/Tg). • Poor proppant quality/excessive crush. • Poor well design and casing integrity. • Horizontal or T-Shaped Fractures. • In-Situ Stress Ordering (sv< sh< sH) • Horizontal and T-Shaped Fractures • Heavily Gel-Damaged Vertical Well. • Frac Parallel Boundaries and kv/kh. 32

  8. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” • Pre-Review • Fracturing close to or above the overburden for 30 years. • Horizontal Fracs with poor or non-existent delivery/uplift. • Also clearly a complex form of relationship for PPFG. • Post-Review • Fracturing below the value of overburden consistently. • Pore-Pressure depletion has reduced horizontal stresses. • Stress reduction not quite as consistent as we would expect. 33

  9. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” 34

  10. THE “FRACTS” OF LIFE Geo-Mechanics “Issue” 35

  11. THE “FRACTS” OF LIFEGeoMechanics Summary • A deep understanding of the actual in-situ stress-state is essential. • There are very few valid ‘rules-of-thumb’ that are safe to use. • When BHTP crosses the 2nd or even 3rd stress then expect issues. • Micro-Frac (WFT) is an excellent surveillance method in new areas. 36

  12. THE “FRACTS” OF LIFE Five Key Aspects • GEOMECHANICS Geometry is the basis of delivery • PERMEABILITY Need accurate order of magnitude of kh 37

  13. THE “FRACTS” OF LIFEPermeability “Issue” • We must use all available techniques to estimate. Linear Flow DP = (P(t) – Pi)=MLFL(t) Radial Flow DP = (P(t) – Pi)=MRFR(t) Two distinct Flow Regimes so we MUST know PR wth reasonable accuracy. 38

  14. THE “FRACTS” OF LIFEPermeability “Issue” • Highly accurate early estimation of kh for design and planning. • 80 bbls of KCl, 8 bpm and 23 hours of shut-in decline, 8.07 mD.ft. • 1 MM.Lb Frac, 30 Day Flow, 500 Day PBU = 7.2 mD.ft First 7 Appraisal wells comparison of ACA with PBU Understanding kh created 7 Tcf opportunity 39

  15. THE “FRACTS” OF LIFEPermeability Summary • As the rock quality reduces, the petro-physics becomes “challenging”. • Log derived k in tight rock often inaccurate (1 or 2 orders of magnitude). • ACA (DFIT) is quick, accurate & ideally suited to E&A environments. • kh is key, importance of early/accurate assessment is fundamental. 40

  16. THE “FRACTS” OF LIFE Five Key Aspects • GEOMECHANICS Geometry is the basis of delivery • PERMEABILITY Need accurate order of magnitude of kh • FRAC QA/QC Defines the Success or the Failure 41

  17. THE “FRACTS” OF LIFEQA/QC “Issue” 42 Photos of debris, from Manifold and Pumps.

  18. THE “FRACTS” OF LIFEQA/QC “Issue” Operator: Right pump it past the surface lines and clear of the tree-saver but not as far as the perforations; then RU CT and clean this mess out. Operator: What is going on, we are only pumping gel ?Service Co: No idea, interested in buying some Perf Guns ? Operator: No it cannot be perforations look at the gauges ?Service Co: Must be the Tree then, whose SCSSV did you run ? Operator: There is a Tree-saver in and we do not have a SCCSV, but we did buy our own in-line viscometer, so why are we pumping 400 cP LG (Pre X-Link) ? 43

  19. THE “FRACTS” OF LIFEQA/QC Summary • QA/QC must be established quickly in new areas to deliver basics. • Fundamental system cleanliness often an issue (especially start-up). • Complex fluid system skills and knowledge, are being forgotten. • Evidence that automation is surpassing/even exceeding capability. 44

  20. THE “FRACTS” OF LIFE Five Key Aspects • GEOMECHANICS Geometry is the basis of delivery • PERMEABILITY Need accurate order of magnitude of kh • FRAC QA/QC Defines the success or the Failure • HORIZONTALS Understand Vertical frac behaviour 45

  21. THE “FRACTS” OF LIFE Horizontals “Issue” • Fully perforated interval gives extensive fracture height. • Stress variation can create ‘corrugated’ fractures. • Land Horizontal in one lens and Frac can be confined. • Confinement can push the BHTP above sH and even sV 46

  22. THE “FRACTS” OF LIFE Horizontals “Issue” • There are “Trade-Offs” when moving from Vertical to Horizontal wells, which the user must appreciate. • Knowledge of the Vertical fracture growth behaviour is absent. • Logs not representative of what the frac actually encounters. • Almost all staging techniques result in some amount of over-flush. • Partial mono-layer/infinite conductivity is a strategic compromise. 47

  23. THE “FRACTS” OF LIFEHorizontals Summary • Why does Vertical dimension no longer concern us ? • Frac Height/Landing point requires early knowledge/data gathering. • As Horizontals ‘move’ into good k/kh, we must do Engineering. • ‘Staging’ developed for ultra-low perm., not broadly applicable. • Popular ‘pillar fracs’, insist on extensive proppant near wellbore. 48

  24. THE “FRACTS” OF LIFE Five Key Aspects • GEOMECHANICS Geometry is the basis of delivery • PERMEABILITY Minimum accurate order of magnitude • FRAC QA/QC Defines the success or the failure • JOURNEY through V to H Understand Vertical frac behaviour • There is always more to learn so expect the unexpected. 49

  25. Your Feedback is Important Enter your section in the DL Evaluation Contest by completing the evaluation form for this presentation Visit SPE.org/dl #SPEDL Society of Petroleum Engineers Distinguished Lecturer Program www.spe.org/dl 50

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